Los Angeles, May 25 : Barbara Ogburn was waiting for guests to arrive for a dinner party when her Siamese cat Toby went to use his litter box.

"The guest bathroom smelled horrible and there was litter everywhere," Ogburn said. "I looked at him and said, `Dude, your litter box is gone."'

Someone had given Ogburn a Litter Kwitter, a three-step training kit that teaches cats to use a toilet instead of a litter box. She decided to try it, and it worked.

Now Ogburn, who's had cats since she was a child, says she will never again have a litter box. No more buying litter, lugging it home, or cleaning it up.

Litter Kwitter and other toilet-training kits on the market for cats work like this: The toilet seat is fitted with a series of plastic rings the cat can step on so it doesn't fall in.

The hole in the rings gets larger over time, until the cat can simply balance on the toilet seat.

But training a cat to use the toilet is not as easy as getting a cat to use a litter box.

Cats instinctively bury their waste to hide it from predators, and litter fosters that instinct in a way that using the toilet does not, according to Steve Duno of Seattle, Washington, a veteran pet behaviorist and trainer who has written 18 books.

That is why, when switching to the toilet, some cats will scrape the bowl, the tank or the wall next to the toilet.

Outdoor cats are not good candidates for toilet-training.

In addition, some cats tolerate change in their routines, while for others, even a slight change in feeding schedules will make their worlds fall apart, said Dr.

Meghan E. Herron, chief veterinarian at the Behavioral Medicine Clinic, part of the Department of Veterinary Clinical Services at Ohio State University.

"Cats are slaves to routine and very wary of danger to themselves," Duno said.

Also there is nothing about the size or height of a toilet that is normal to a cat, Herron said.

"One bad experience with a toilet can make them never use it again," she said.

Duno, who has toilet-trained several cats, says he has known cats that have fallen into the toilet and "that's it: you're done right there."

When you talk about toilet-trained cats, most people think of Mr. Jinx, Robert De Niro's beloved, toilet-flushing, mayhem-making cat in "Meet the Parents," "Meet the Fockers" and "Little Fockers."

Dawn M. Barkan trained all the Himalayan cats that portrayed Mr. Jinx in those movies, including two rescued cats, Peanut and Charlie, who still live with her.

Misha, who has since died, did the original scene, but "we didn't really train him to use the toilet," said Barkan, who freelances for Los Angeles-based Birds & Animal Unlimited. "It's movie magic."

The cat sat on a prop designed to look like a toilet and pressed a button so that the toilet appeared to be flushed. Sound effects were added later.

The idea for Litter Kwitter came from "Meet the Parents," said Jo Lapidge, who with her husband Terry invented the kit.

After research and tests, the Sydney, Australia, couple launched their company in 2005. Since then, they've sold 750,000 kits.

Lapidge says the kit has an 80 percent success rate that "would be higher if humans stopped to follow all the instructions and showed a bit more patience."

In addition to toilet-training products with plastic rings -- ranging in price from lightweight plastic for about $10 to Litter Kwitter at $50, also online are how-to sites and books that explain how to toilet-train your cat.

Online customer reviews for the products are mixed.

Even those who say they have been successful often say it took several months to complete the training, with the cat having accidents along the way.

One commenter for a toilet-training kit for a product called CitiKitty gave it five stars but cautioned that the process was "messy."

There is one disadvantage for cat-owners who successfully train their animals. Owners may be alerted to health problems by how often a cat uses its litter box or the odor, color or texture of waste. With a toilet, "you can't monitor the cat's health through elimination evidence," Duno said.

In addition, as a toilet-trained cat ages, it may have a hard time leaping onto the seat.

Herron cautioned that a cat is likely to find another place to go rather than wait in line at a bathroom door, so a spare or guest bathroom the animal can use works best.

One benefit in addition to doing away with litter: Toilets diminish the risk of humans contracting parasites or infectious diseases like toxoplasmosis, ringworm or tapeworm from cat waste.

Finally, no matter how happy you might be to have toilet-trained your cat, Duno said this is one animal behavior that should not be rewarded with a treat.

"You are choreographing it, but you are not actively encouraging it," Duno said.